ext4: refine extent status tree

This commit refines the extent status tree code.

1) A prefix 'es_' is added to to the extent status tree structure
members.

2) Refactored es_remove_extent() so that __es_remove_extent() can be
used by es_insert_extent() to remove the old extent entry(-ies) before
inserting a new one.

3) Rename extent_status_end() to ext4_es_end()

4) ext4_es_can_be_merged() is define to check whether two extents can
be merged or not.

5) Update and clarified comments.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 077f82d..81e9339 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -22,8 +22,8 @@
 
 struct extent_status {
 	struct rb_node rb_node;
-	ext4_lblk_t start;	/* first block extent covers */
-	ext4_lblk_t len;	/* length of extent in block */
+	ext4_lblk_t es_lblk;	/* first logical block extent covers */
+	ext4_lblk_t es_len;	/* length of extent in block */
 };
 
 struct ext4_es_tree {
@@ -35,9 +35,9 @@ extern int __init ext4_init_es(void);
 extern void ext4_exit_es(void);
 extern void ext4_es_init_tree(struct ext4_es_tree *tree);
 
-extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t start,
+extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 				 ext4_lblk_t len);
-extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t start,
+extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 				 ext4_lblk_t len);
 extern ext4_lblk_t ext4_es_find_extent(struct inode *inode,
 				struct extent_status *es);